(1) Field of the Invention
The present invention relates to a recording composite sheet. More particularly, the present invention relates to a recording composite sheet capable of being easily and stably printed and having two sheet sections bonded to each other and separable from each other by hand as desired.
(2) Description of the Related Art
As means for recording information in colored images, various systems, for example, an electrophotographic recording system, an ink jet recording system, a thermal transfer recording system and a thermosensitive recording system are available. Among these systems, the thermal transfer recording system and ink jet recording system can record full color clear images and thus are attractive.
In the thermal transfer recording system, a sublimating dye-contacting layer or a thermally melting ink-containing layer of an ink sheet is brought into contact with a dye or ink melt-receiving layer of a recording sheet, the superposed sheets are heated imagewise by heating means, for example, a thermal head, so as to thermally transfer imagewise the dye or ink melt to the image-receiving layer and to form dye or ink colored images having a desired form and color density on the ink-receiving layer.
The dye or ink-containing sheet contains yellow, magenta, cyan or optionally black-colored dye or ink.
Full colored images can be formed by superposing the above-mentioned colored images having a desired form and color density on each other. The above-mentioned thermal transfer recording sheets are expected to be widely utilized to record clear full colored images.
In the ink jet recording system, inks can be jetted imagewise toward an ink-receiving layer of an ink jet recording sheet through ink-jetting means incorporated to an ink jet printer. In the ink jet recording system, clear full colored images can be formed by using a plurality of colored inks different in hue from each other. Therefore, the ink jet recording system is expected to be widely utilized in various full-colored image-recording fields. As mentioned above, with advance and spread of the printing technology, various requirements are applied to the recording sheets. For example, those are demands of providing a thin recording sheet having a thickness of 100 .mu.m or less, particularly 60 .mu.m or less, usable, without difficulty, for above-mentioned recording systems; a recording composite sheet capable of being printed on the front and back surfaces thereof and being separated into a front sheet section and a back sheet section by hand; and a recording composite sheet capable of containing visible images in an invisible inside part of the sheet, and of being separated, by hand, into a front sheet section and a back sheet section to thereby make appear the visible images contained in at least one of the sheet sections.
Usually, in the conventional composite sheet, the front sheet section and the back sheet sections are bonded to each other through a pressure-sensitive adhesive layer. When the conventional composite sheet is peeled into the two sheet sections, at least one of the sheet sections has the pressure-sensitive adhesive layer.
The conventional composite sheet is unsuitable for the use in which the separated sheet sections should have no pressure-sensitive adhesive surfaces.